A grease for a slide contact has been used for a sliding switch and the like of a vehicle such as an automobiles and the like. The following properties are required of the grease in particular because it is troublesome and cost much labor to apply the grease to slide contact parts and slide parts made of resins respectively:
(i) It indicates low frictional resistance when it is applied to the slide parts made of resins or metals. PA1 (ii) It does not affect Environment Stress Crack of slide parts made of resins. PA1 (iii) It does not corrode the contact parts made of metals such as copper, and maintains low contact resistance of the contact parts under corrosive environments such as high temperature and humidity conditions. PA1 (iv) It extinguishes arc generated at the time of switching a load-break when it is applied to breaking parts of the slide contact, and is hard to deteriorate and carbonize under arc heat. PA1 (v) It does not change in quality at the temperatures used for soldering a lead wire, and makes a process for soldering the lead wire possible after it is applied to the slide contact. PA1 (vi) It can comprise a coloring agent without losing the aforementioned properties (i)-(v).
In addition to the above, the following property is required of the grease from the viewpoint that a poor dispersion of the ingredients, a bad injection of the grease from an autoapplicator, and the presence of the grease applied to members made of white or whitey resins, which constitute the switch, can visually be confirmed:
Although a grease for a slide contact possessing the aforesaid properties (i)-(v) (cf. U.S. patent application Ser. No. 07/753,374), there is yet room for improvement in the property (iv), and increase of a repeated durability of the switch is required of said grease in particular. Furthermore, as said grease is nearly colorless, the poor dispersion of ingredients, and the like cannot be confirmed visually.